I am having the same issue on my nexus 4, but, according to android forums, other phone brands using Android are experiencing the same problem so I feel it is due to the recent upgrade of Android.
I use Ptel (a secondary that uses T Mobile's towers) and they are aware of the problem but haven't solved it. Because I cannot find other people having texting issues on this forum, I am thinking the problem is with the carrier. Thanks for responding.
I am using PTel (Platinum Tel) and found them to be awesome...coverage is great and found their signals to be stronger than T Mobiles...I strongly recommend them...I have unlimited phone, internet and text for $40 a month.
Yes, I am having the same issues with mine. Have tried the reboot to safe mode and it functions for a while then starts again. Mine is running android 4.4.2 and I pray a software update will solve the problem